September 3, 1968

Professor Arthur R. Jensen
Institute of Human Learning
University of California
2241 College Avenue
Berkeley, California 94720

Dear Professor Jensen:

Thank you for your article which I read with interest and can
scarcely quarrel with. The only caution I would have added
would be the fallacy, exploited by some of our mutual acquaintances,
of extrapolating measures of heritability estimated in a white
and not too heterogeneous socio-economic group as being pertinent
to the genetic basis of differences {in performance between black
and white subcultures. So far as I know there have been no
adoption studies on black children at ail, much less those who
might be transplanted to white environments. Even if such were
to be attempted, I would still be concerned that the white
reaction to black skin remained an intangible but significant
part of the demonstrable performance.

I realize your paper does not directly deal with this issue and,

of course, I must continue to applaud your pleas for looking for

ways to measure individual variability precisely for the purposes
of improving the corresponding fitness of the environment.

Sincerely yours,

J. Lederberg
Professor of Genetics

JL/mla

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